Caster.



A. GRUBBA & J. PONKE.

CASTER.

APPLICATION FILED APR.26. 1915.

Pawnted Aug. 3, 1915.

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coL NOGRAPH 20.. WASHINGTON D c ANTHONY GRUBZBA AND JOSEPH PONKE, 0F ROYAL OAK, MICHIGAN.

CASTER.

Specification of Letters Patent.

Patented Aug. 3, 1915.

Application filed April 26, 1915. Serial No. 24,078.

To all whom it may concern:

Be it known that we, ANTHONY GRUBBA and JosEPH PONKE, citizens of the United States of America, residing at Royal Oak, in the county of Oakland and State of Michigan, have invented certain new and useful Improvements in Casters, of which the following is a specification, reference being had therein to the accompanying drawmgs.

In the use of casters for furniture and more particularly those for heavy articles such as pianos it is desirable that the casters turn or roll in whichever direction they are moved, instantly, without having to swing into line on their swivel as in common in the conventional type of such articles. It is also desirable that the parts be so arranged and disposed as to turn easily regardless of the weight thereon.

This invention relates to casters for furniture, and like articles, and to an arrangement thereof whereby each caster commences to roll when moved in any direction, from the position of rest without waiting to be turned into line or into a certain angle coincident with the path of motion.

The invention also includes means whereby friction is eliminated to a very great extent and to simplicity of construction whereby the articles can be made in large numbers very cheaply and rapidly.

The invention consists in the matters hereinafter set forth and more particularly pointed out in the appended claim.

In the drawings, the figure is a view partially in longitudinal or vertical section and partially in elevation, showing a caster that embodies features of the invention, the article being slightly tilted toward the observer.

Referring to the drawings, a cylindrical shell 1, preferably of sheet metal, has a flared flange 2 at its upper end over which the depending rim flange 3 of a cap 4 is formed to secure the parts together, a plate 5 being interposed and secured between the flanges. A main bearing ball 6 of such diameter as to turn freely in the bushing or member 1, in which it is retained by a removable annular retainer 7 that is pressed over and on to the slightly undercut rim of the member 1, bears upwardly against a plurality of anti-friction balls 8 that run in raceway 9 formed in the member 5. The balls are so spaced that the bearing ball 6 protrudes sufficiently from the member 1 to roll freely on a floor or'the like and still be retained by the annular member 7 which is of slightly less diameter than the ball. A spindle 10 is secured to the cap as by being headed over an inner annular flange 11 formed in a central upper opening of the cap. As a result of this construction a caster is obtained that rolls freely in all directions, that is readily machined and assembled and that carries any weight without binding, there being no necessity for swinging the caster into a certain plane coincident with the path of motion in order to have the caster revolve.

Obviously, changes in the details of construction may be made without departing from the spirit of the invention and we do not care to limit ourselves to any particular form or arrangement of parts.

What we claim is A caster comprising a sheet metal upright shell having a flared upper rim flange, a plate having a ball raceway on its lower face and resting on the flared shell end, a cap resting on the plate and having a depending flange interlocking with the flared shell end over the margin of the raceway plate, a main bearing ball rotatably fitting in the shell spacing balls in the raceway of the plate maintaining the main bearing ball in operative relation to the lower end portion of the shell, and an annular retaining member over the main ball detachably engaging the lower end portion of the shell.

In testimony whereof we affix our signatures in presence of two witnesses.

ANTHONY GRUBBA. JOSEPH PONKE. Witnesses:

ANNA M. DORR, C. R. STIOHNEY.

Copies of this patent may be obtained for five cents each, by addressing the Gommissioner of Patents, Washington, D. O. 

